| Message ID | 1390981411-16146-1-git-send-email-yamato@redhat.com |
|---|---|
| State | Accepted, archived |
| Delegated to: | David Miller |
| Headers | show |
From: Masatake YAMATO <yamato@redhat.com> Date: Wed, 29 Jan 2014 16:43:31 +0900 > A file descriptor opened for /dev/net/tun and a tun device are > connected with ioctl. Though understanding the connection is > important for trouble shooting, no way is given to a user to know > the connected device for a given file descriptor at userland. > > This patch adds a new fdinfo field for the device name connected to > a file descriptor opened for /dev/net/tun. > > Here is an example of the field: ... > Signed-off-by: Masatake YAMATO <yamato@redhat.com> This looks a lot better, applied, thanks. -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/drivers/net/tun.c b/drivers/net/tun.c index bcf01af..44c4db8 100644 --- a/drivers/net/tun.c +++ b/drivers/net/tun.c @@ -69,6 +69,7 @@ #include <net/netns/generic.h> #include <net/rtnetlink.h> #include <net/sock.h> +#include <linux/seq_file.h> #include <asm/uaccess.h> @@ -2228,6 +2229,27 @@ static int tun_chr_close(struct inode *inode, struct file *file) return 0; } +#ifdef CONFIG_PROC_FS +static int tun_chr_show_fdinfo(struct seq_file *m, struct file *f) +{ + struct tun_struct *tun; + struct ifreq ifr; + + memset(&ifr, 0, sizeof(ifr)); + + rtnl_lock(); + tun = tun_get(f); + if (tun) + tun_get_iff(current->nsproxy->net_ns, tun, &ifr); + rtnl_unlock(); + + if (tun) + tun_put(tun); + + return seq_printf(m, "iff:\t%s\n", ifr.ifr_name); +} +#endif + static const struct file_operations tun_fops = { .owner = THIS_MODULE, .llseek = no_llseek, @@ -2242,7 +2264,10 @@ static const struct file_operations tun_fops = { #endif .open = tun_chr_open, .release = tun_chr_close, - .fasync = tun_chr_fasync + .fasync = tun_chr_fasync, +#ifdef CONFIG_PROC_FS + .show_fdinfo = tun_chr_show_fdinfo, +#endif }; static struct miscdevice tun_miscdev = {
A file descriptor opened for /dev/net/tun and a tun device are connected with ioctl. Though understanding the connection is important for trouble shooting, no way is given to a user to know the connected device for a given file descriptor at userland. This patch adds a new fdinfo field for the device name connected to a file descriptor opened for /dev/net/tun. Here is an example of the field: # lsof | grep tun qemu-syst 4565 qemu 25u CHR 10,200 0t138 12921 /dev/net/tun ... # cat /proc/4565/fdinfo/25 pos: 138 flags: 0104002 iff: vnet0 # ip link show dev vnet0 8: vnet0: <BROADCAST,MULTICAST,UP,LOWER_UP> mtu 1500 ... changelog: v2: indent iff just like the other fdinfo fields are. v3: remove unused variable. Both are suggested by David Miller <davem@davemloft.net>. Signed-off-by: Masatake YAMATO <yamato@redhat.com> --- drivers/net/tun.c | 27 ++++++++++++++++++++++++++- 1 file changed, 26 insertions(+), 1 deletion(-)